Add service input plugin for OpenConfig streaming telemetry (#2292)

plugins/inputs/jti_openconfig_telemetry/auth/authentication_service.proto

@@ -0,0 +1,48 @@
+//
+// Copyrights (c) 2017, Juniper Networks, Inc.
+// All rights reserved.
+//
+
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+//
+
+syntax = "proto3";
+
+package authentication;
+
+// The Login service definition.
+service Login {
+  rpc LoginCheck (LoginRequest) returns (LoginReply) {}
+}
+
+// The request message containing the user's name, password and client id
+message LoginRequest {
+  string user_name = 1;
+  string password   = 2;
+  string client_id = 3;
+}
+
+/*
+ * The response message containing the result of login attempt.
+ * result value of true indicates success and false indicates
+ * failure
+ */ 
+message LoginReply {
+  bool result = 1;
+}